Nanoporous Membrane and Method of Preparation Thereof

Abstract

A nanoporous membrane structure characterised in that it has a hexagonal array of tubes with a substantially uniform inter-pore distance between the tubes wherein the distance is within the range from 10-500 nm and wherein the tubes may have a depth of up to 500 μm.

1 . A nanoporous membrane structure characterised in that it has a hexagonal array of tubes which open with pores wherein there is a substantially uniform inter-pore distance between the tubes and wherein the distance is within the range from 10-500 nm and wherein the tubes have a depth of up to 500 μm. 
   
   
       2 . A nanoporous membrane structure according to  claim 1  wherein the tubes are aligned substantially perpendicular to the surface of the membrane. 
   
   
       3 . A nanoporous membrane structure according to  claim 1  wherein the density of the pores is between the range from 10 9  to 10 12  pores/cm 2 . 
   
   
       4 . A nanoporous membrane structure according to  claim 1  wherein the inter-pore distance is within the range from 50 to 350 nm. 
   
   
       5 . A nanoporous membrane structure according to  claim 1  wherein the inter-pore distance gradually decreases from the periphery of the membrane to the centre of the membrane. 
   
   
       6 . A nanoporous membrane structure according to  claim 1  wherein the inter-pore distance gradually increases from the periphery of the membrane to the centre of the membrane. 
   
   
       7 . A nanoporous membrane structure according to  claim 1  wherein the membrane comprises a hexagonal array of tubes with a substantially uniform inter-pore distance towards the centre of the membrane but a different uniform inter-pore distance towards periphery of the membrane. 
   
   
       8 . A method for preparing a nanoporous membrane, comprising the steps of:
 (a) preparing an aluminium film;   (b) subjecting the aluminium film to a first anodising step;   (c) subjecting the aluminium film to wet chemical etching;   (d) subjecting the aluminium film to a second anodising step, wherein the conditions employed in this step are similar to or substantially the same as the conditions as used in the first anodising step.   
   
   
       9 . A method according to  claim 8  wherein the first anodising step is carried out using a constant voltage and an aqueous solution of an acid. 
   
   
       10 . A method according to  claim 9  wherein the constant voltage ranges from between about 15 to about 200 volts. 
   
   
       11 . A method according to  claim 10  wherein the constant voltage is selected from 24 volts, 30 volts, 60 volts or 200 volts. 
   
   
       12 . A method according to  claim 9  wherein the aqueous acid solution is selected from sulphuric acid, oxalic acid, phosphoric acid, chromic acid, tartaric acid and malonic acid. 
   
   
       13 . A method according to  claim 9  wherein the voltage is 30 V and the aqueous acid solution is oxalic acid. 
   
   
       14 . A method according to  claim 9  wherein the voltage is 60 V and the aqueous acid solution is oxalic acid. 
   
   
       15 . A method according to  claim 9  wherein the voltage is 24 V and the aqueous acid solution is sulphuric acid. 
   
   
       16 . A method according to  claim 9  wherein the voltage is 60 V and the aqueous acid solution is phosphoric acid. 
   
   
       17 . A method according to  claim 9  wherein the voltage is 200 V and the aqueous acid solution is tartaric acid. 
   
   
       18 . A method according to  claim 9  wherein the voltage is 90 V and the aqueous acid solution is malonic acid. 
   
   
       19 . A method according to  claim 8  A method according to any one of  claims 8  to  18  wherein the first anodising step is carried out at a temperature from 0° C. to room temperature. 
   
   
       20 . A method according to  claim 8  further comprising the steps of:
 (e) contacting the aluminium film from step a with a material capable of supporting the film;   (f) suspending the aluminium film in a solution which completely removes the unprotected aluminium substrate; and   (g) removing the layer of oxide to produce nano-channels throughout the alumina film.   
   
   
       21 . A method according to  claim 8  wherein the aluminium film of step (a) has a protective layer applied to one side of the aluminium film prior to the first anodising step of step (c). 
   
   
       22 . A nanoporous membrane structure produced by the method of  claim 8 . 
   
   
       23 . A method of preparing a nanoporous membrane structure coated with viable cells comprising the steps of contacting a nanoporous membrane structure with a suspension of cells for a period of time sufficient to deposit cells onto the membrane. 
   
   
       24 . A method for preparing a homogenous population of cells, wherein the method comprises the steps of:
 (a) manufacturing a nanoporous membrane structure;   (b) growing cells on the nanoporous membrane structure; and   (c) harvesting the cells from the membrane.   
   
   
       25 . A method of treating a patient in need of tissue damage repair, said method comprising the steps of:
 (a) manufacturing a nanoporous membrane structure;   (b) growing cells on the nanoporous membrane structure; and   (c) applying cell coated nanoporous membrane structure to a wound.   
   
   
       26 . A method of treating a patient in need of tissue damage repair, said method comprising the steps of:
 (a) manufacturing a nanoporous membrane structure;   (b) contacting the nanoporous membrane structure with a solution of cultured cells; and   (c) applying the nanoporous membrane structure coated with ceils to the site of tissue damage.